Magnetic escapement



Sept. 15, 1964 V Filed Sept. 29. 1960 G. GLASER ETAL MAGNETIC ESCAPEMENT2 Sheets-Sheet 1 INVENTORS 621s er Sept. 15, 1964 G. GLAsER E'rAl.3,149,269

MAGNETIC EscAPEMEN'r Filed sept. 29. 1960 2 sheets-sheet 2 United StatesPatent O 3,149,269 MAGNETIC ESCAPEMENT Gnther Glaser, Parzelleuhle AntonKopp, Bahnhofstrasse 14; and Alfons Lamprecht, Marktstr-asse 13, all

of Schramberg, Germany Filed Sept. 29, 1960, Ser. No. 59,448 Claimspriority, application Germany Oct. 1, 1959 5 Claims. (Cl. 317-201) Theinvention relates to a magnetic escapement with an oscillator comprisingan oscillating spring and a magnet composed of at least two laminapieces at least partly congruent which are stamped from sheet metal andheld together preferably by a bridge-shaped run-through safety stopprovided with rivet lugs engaging in punched apertures. In such magneticescapements the individual laminae of the magnets are, according to anearlier invention of the applicant, held together at one end by therun-throughsafety stop and at the other end by fixing means connectingthe magnet to the oscillating spring. Hereby it may happen that thelaminae do not lie flat one on the other between the holding means butgape slightly. This can cause asymmetry in the oscillatable assembly bywhich the natural frequency an amplitude of oscillation are iniiuenced.This objection cannot, however, be overcome by a special treatment ofthe oscillating spring. Such an oscillator is therefore often useless.

According to the invention the individual laminae forming the magnet areconnected together by metal cement in addition to the tixing means forthe oscillating spring and eventually also for the run-through safetystop. The magnet may, for example consist of only one continuous laminaon the poles of which additional lamina pieces are fixed. The additionallamina pieces are preferably arranged on both sides of the poles of thecontinuous lamina. By this means any change in the symmetry of themagnet caused by the fixing means of the oscillating spring and of therun-through safety stop is prevented in a very reliable manner.

The invention is hereinafter explained in greater detail with referenceto the accompanying drawings, in which:

FIGS. l and 2 show a magnet composed of two continuous laminae in sideelevation and in plan view respectively;

FIGS. 3 and 4 are similar views of a magnet composed of only onecontinuous lamina on the poles of which additional lamina pieces areplaced;

FIGS. 5 and 6 show in plan view and front elevation respectively amagnet according to FIGS. 3 and 4 in which lamina pieces are fitted onboth sides of the poles, and

FIGS. 7 and 8 show a magnet in which the run-through safety stop fixingthe additional lamina pieces is constructed in a special manner, FIG. 7being atop plan View and FIG. 8 a front elevation in which the leftportion of the magnet is in section taken on line VIII-VIII of FIG. 7.

In FIGS. 1 and 2, the two continuous laminae forming the horse-shoemagnet are designated by 10 and 11. Onto the surfaces of the laminae 10and 11 facing each other a high-grade metal cement is applied, whereuponthe laminae are pressed together and connected to the oscillating spring13 by rivets 12 while the run-through safety stop 14 is wedged by meansof its rivet lugs 15 in dove-tail guides 16. Instead of applying themetal cement before riveting the laminae, the laminae can iirst beriveted to- 3,149,269 Patented Sept. l5, 1964 gether and then bentslightly asunder in the middle between the rivets with the aid of atool, whereupon they are smeared with metal cement and finally pressedtogether again. The pressing togther of the laminae 10 and 11 and thesetting of the metal cement can be effected in a relatively short timeand is dependent upon the kind of cement employed, and Whether it iscarried out in cold state or whether a heating arrangement is employed.To prevent the laminae from gaping, the magnet may be composed, forexample according to FIGS. 3 and 4, of only one continuous lamina 10 ofthe same thickness as the lamina 16 shown in FIGS. l and 2. In this caseadditional lamina pieces 17 and 18 are placed on the poles of the lamina10 and are of the same thickness as the continuous lamina 10. The laminapieces are adapted to the shape of the poles of the continuous lamina 10and, like the continuous lamina, have dove-tail guides 16 in which therun-through safety stop 14 is inserted and riveted. It has been foundthat the same high constant magnetic force is obtained as with a magnetaccording to FIGS. 1 and 2 composed of two continuous laminae.

In the embodiment illustrated by way of example in FIGS. 5 and 6additional lamina pieces 17, 18 and 19, 20 are placed on both sides ofthe poles of the continuous lamina 10 in order to obtain a somewhatgreater magnetic force. The additional lamina pieces 17, 18, 19, 20 arealso in this case cemented to the continuous lamina and connected byriveting with the run-through safety stop 14. The run-through safetystop has, however, in this case only somewhat longer riveting lugs 21.

In the form of construction according to FIGS. 7 and 8, a particularlygood bearing of the additional lamina pieces 23 and 24 against thecontinuous lamina 25 is attained by giving the run-through safety stop22 a special shape. The ends of the safety stop 22 connecting the polesof the magnet are bent at an angle in relation to the middle portion.Oval holes 26 are punched in the poles of the continuous lamina 2S andin the additional lamina pieces 23 and 24 and the rivet lugs 27 of therun-through safety stop are inserted in these holes and upset. Therun-through safety stop thus bears against the lamina 25 and the laminapieces 23 and 24 along a relatively long stretch with the result thatthese lamina pieces bear tightly. At the same time, however, therun-through safety stop is hereby given a better hold and, after beingriveted, positively assumes the correct position so that subsequent workis unnecessary. It is evident that a suitably bent run-through safetystop can also be employed on the magnets composed of two or morecontinuous laminae shown in FIGS. 1 and 2.

We claim:

1. A magnetic escapement with an oscillator comprising an oscillatingspring and a magnet defining pole pieces and composed of at least two atleast partly congruent lamina pieces of sheet metal held together by ametal cement and a bridge-shaped run-through safety stop engaging inpunched apertures and provided with rivet lugs.

2. A magnetic escapement according to claim 1, in which additionallamina pieces are provided with the additional lamina pieces provided onthe poles of the magnet, said magnet being composed of at least onecontinuous lamina.

3. A magnetic escapement according to claim l, in which additonal laminapieces are provided with the additional lamina 'pieces provided on thepoles of the magnet, said magnet being composed of at least onecontinuous lamina, and the additional lamina pieces being arranged onboth sides of the poles of the continuous lamina.

4. A magnetic escapement according to claim 1, in which the ends of therunthrougl1 safety stop connecting the magnet pole pieces are bent at anangle relative to, the middle part and in the direction of, thelongitudinal axis of the oscillator.

5. A magneticescapement according to claim 1, in which the ends of therun-through safety stop connecting ,the magnet pole pieces are bent atan angle relative to,

4 the middle part and in the direction of, the longitudinal axis of theoscillator, and in which the magnet has in its pole pieces slotted holesextending in the direction of the bent ends of the run-through safetystop for xing said 5 stop.

References Cited in the le of this patent UNITED STATES PATENTS 102,423,869 Blessing July 15, 1947 2,941,417 Junghans et al June 21, 19602,970,077 Groves Jan. 31, 1961

1. A MAGNETIC ESCAPEMENT WITH AN OSCILLATOR COMPRISING AN OSCILLATINGSPRING AND A MAGNET DEFINING POLE PIECES AND COMPOSED OF AT LEAST TWO ATLEAST PARTLY CONGRUENT LAMINA PIECES OF SHEET METAL HELD TOGETHER BY AMETAL CEMENT AND A BRIDGE-SHAPED RUN-THROUGH SAFETY STOP ENGAGING INPUNCHED APERTURES AND PROVIDED WITH RIVET LUGS.